Apparatus and method for winding coil springs

ABSTRACT

A method and apparatus for winding coil springs in which the spring wire is supplied to a bending location at a substantially constant feed rate and is sequentially bent for predetermined periods of time at a first fixed radius of curvature, a first variable radius of curvature, a second fixed radius of curvature, and a second variable radius of curvature, the bending steps being repeated a predetermined number of times and the spring wire then being cut such that a spring having a predetermined number of identical, multiradius coils is formed.

United States Patent Arnold Peter LeVasseur Lakeville, Minn.

Oct. 10, 1968 Apr. 27, 1971 North American Rockwell CorporationPittsburgh, Pa.

Inventor Appl. No. Filed Patented Assignee APPARATUS AND METHOD FORWINDING COIL SPRINGS 23 Claims, 7 Drawing Figs.

US. Cl 72/33, 72/132, 72/138, 140/103 Int. Cl ..B2lc 51/00, B2lf3/00,B2lf 1 1/00 Field of Search 72/138,

[56] References Cited UNITED STATES PATENTS 2,455,863 12/1948 Halvorsen72/138 3,009,505 11/1961 72/33 3,342,052 9/1967 72/138 3,472,051 10/196972/138 Primary Examiner-Charles W. Lanham Assistant Examiner-R. M.Rogers Attorneys-George R. Powers and John R. Bronaugh ABSTRACT: Amethod and apparatus for winding coil springs in which the spring wireis supplied! to a bending location at a substantially constant feed rateand is sequentially bent for predetermined periods of time at a firstfixed radius of curvature, a first variable radius of curvature, asecond fixed radius of curvature, and a second variable radius ofcurvature, the bending steps being repeated a predetermined number oftimes and the spring wire then being cut such that a spring having apredetermined number of identical, multiradius coils is formed.

PATENTEB m2? I97! 3576.120

sum 2 or 3 @WWWV'Q- FIG. 3

PATENTED APR 27 1971 sum 3 0F 3 APPARATUS AND METHOD FOR WINDING COILSPRINGS This invention relates to the winding of coil springs and, moreparticularly, to a method and apparatus for winding coil springs havingnonuniform radii of curvature. The invention is particularly suited tothe winding of coil springs of the type described and claimed bycopending Pat. application Ser. No. 711,774, entitled Coil Spring. filedMar. 8, 1968 in the name of Glenn E. Mather and assigned to the assigneeof this invention.

The aforesaid patent application discloses a coil spring adapted forloading in a direction transverse to its coiled or longitudinal axis,each coil of the spring having portions formed on different constantradii joined by relatively short transition portions of varying radii.By controlling the different radii, the spring index, and the springpitchwith accuracy, springs characterized by a broad range ofloaddeflection characteristics, including substantially constant loadcharacteristics, can be produced. Heretofore, it has not been possibleto manufacture coil springs of the type taught by the aforesaid patentapplication in a rapid, efficient and accurate manner.

It is therefore an object of this invention to provide an improvedmethod and apparatus for winding coil springs having nonuniform radii ofcurvature.

Another object is to provide improved means for automatically producingcoil springs of the type disclosed by the aforesaid patent application.

A further object is to provide a rapid, efficient and accurate methodand apparatus for making coil springs having nonuniform coil radii andconstant pitch.

A still further object of the invention is to provide means capable ofautomatically producing a wide variety of coil springs in a rapid,efficient and accurate manner.

Yet another object is to provide a method and apparatus forautomatically winding springs of the foregoing type and automaticallycutting the springs to proper length.

Briefly stated, in carrying out the invention in one form, a spring wireis longitudinally supplied to a bending location at a substantiallyconstant rate and is there sequentially bent at a first fixed radius ofcurvature for a first period of time, at a variable radius for a secondperiod of time, at a second fixed radius for a third period of time, andat a variable radius for a fourth period of time to form a single springcoil, the first and third periods of time being substantially longerthan the second and fourth periods of time. The bending process isrepeated a selected number of times to produce a coil spring having adesired number of coils, the spring simultaneously and continuouslybeing stretched along its longitudinal axis to provide a desiredconstant pitch. The wire is cut after the predetermined number of coilshave been formed to form a discrete spring of predetermined length.

By a further aspect of the invention, the wire is supplied at theconstant feed rate by supporting and guiding means preferably includinga roller engaging the wire, and the wire is bent by forming meansincluding a reciprocable abutment surface movable along the feed axis ofthe wire and an arbor offset from the feed axis. The wire supplied bythe supporting and guiding means strikes the abutment surface and isdeflected therefrom around a bending surface and on the arbor, theradius of curvature of the wire being dependent on the axial spacingbetween the abutment surface and the supporting and guiding means. Meansare provided for interconnecting and coordinating the movement of thewire advancing means and the abutment surface such that the nonuniformradii characteristics of the coils can be controlled with accuracy.Automatic cutoff means are also provided for counting the number ofcoils formed and for cutting the wire when a predetermined number ofcoils have been formed.

While the invention is distinctly claimed and particularly pointed outin the claims appended hereto, the invention, both as to organizationand content, will be better understood and appreciated, along with otherobjects and features thereof, from the following detailed descriptionwhen taken in conjunction with the drawing, in which:

FIG. 1 is an exploded perspective view of a spring winding machineincorporating the invention;

FIG. 2 is an enlarged side view of the wire forming means and the wireadvancing means of the invention;

FIG. 3 is an enlarged view of the abutment means of FIG. 2 illustratingin solid lines its first end position and in broken lines its second endposition;

FIG. 41 is a view taken along viewing line 4-4 of FIG. 3;

FIG. 5 is a perspective view of the means, including a cam and afollower, for reciprocating the abutment surface and a partial view ofthe means for interconnecting the wire advancing means and the means formoving the abutment surface;

FIG. 6 is an enlarged view of the cam and the follower of FIG. 5, theposition of the follow corresponding to the first end position of theabutment surface being shown by solid lines and the positioncorresponding to the second end position being shown by broken lines;and

FIG. 7 is a side view of an alternative form of the invention.

Referring first to FIGS. 1-3, a spring coiling machine 10 formed inaccordance with the invention includes a wire supporting and guidingmechanism 12 for delivering a wire 13 to a coiling location 14, themechanism 12 including rollers 15 for forcing the wire 13 along alongitudinal axis 16 defined by guide plates 17. At least one of therollers 15 is driven by an electric motor 18 or other suitable drivemeans. Adjacent the discharge portion 21 of the guide means 12 is astationary arbor 22 which is offset laterally below the longitudinalaxis 16, the arbor 22 having a smoothly curved bending surface 23 asbest shown by FIG. 3 which is substantially tangent to the longitudinalaxis 16 immediately adjacent the discharge portion 21 and divergesaxially and laterally therefrom to a forward point 25. An abutmentsurface 27 on a block 28 extends transversely across the longitudinalaxis 16 axially spaced from the discharge portion 21. More particularly,the coiling point surface 27 is axially movable between first and secondend positions as illustrated by FIG. 3, the first end positionillustrated by solid lines being a distance x: from the dischargeportion 21, and the second end position illustrated by broken linesbeing a distance x from the discharge portion 21. With the abutmentsurface 27 in either of its end positions, or, for that matter, anywherebetween its end positions, the wire 13 discharged from the dischargeportion 21 will, when once started, be deflected by the coiling point 27out of the longitudinal axis 16 into a curved configuration. Actually,it is desirable that the initial deflection of the wire 13 be directedsuch that the wire is bent around the bending surface 23. When theabutment surface 27 is in its first end position, the wire 13 will bebent at a first constant radius, and when the surface 27 is in itssecond end position, the wire will be bent around the surface 23 at asecond constant radius, the second constant radius being larger than thefirst constant radius since the distance 1 is larger than the distancex,. In the preferred embodiment of the invention, the ratio of thedistance x to the distance x, is 1.422 to 1. It will, of course, beobvious to those skilled in the art that wire bent while the surface 27is at any position between its end positions will have a radius ofcurvature somewhere between the radii of curvature at the end positions.

In accordance with the present invention, the electric motor 18 and therollers 15 advance the wire 13 at a substantially uniform rate to theforming means adjacent the discharge portion 21, and the abutmentsurface 27 is moved between its end positions in a predetermined manner.More particularly, the surface 27 is sequentially maintained in itsfirst end position for a first predetermined period of time, moved toits second end position during a second predetermined period of time,maintained in its second end position for a third predetermined periodof time, and moved to its first end position during a fourthpredetermined period of time. A single coil formed in this manner willhave a first portion of relatively small constant radius formed when theabutment surface 27 is in its first end position, a portion ofrelatively large constant radius formed when the surface 27 is in itssecond end msition, and portions of varying radius formed when theabutment surface 27 is being moved between its end positions. Byscheduling the movement of the surface 27 that the first and third timeperiods are much longer than the second and fourth time periods, theconstant radius portions may be made much longer than the variableradius portions since the wire is supplied by the rollers at a constantrate.

Referring now to FIG. 3, it will be seen that the individual coils arebent inthe plane of the drawing such that the coiled axis of theresulting spring will be normal to the plane of the drawing. To providea constant spring pitch, an adjustable member 30, commonly known as apitch tool, having a flat surface 31 thereon laterally spaced, as bestshown by FIG. 4, a distance x from the axis 16 is provided, the springcoils being directed across the surface 31 after being deflected by thesurface 27. The function of the surface 31 is to longitudinally stretchthe coils along the coiled axis to produce a desired pitch. If it isdesired to vary the pitch, the offset distance x may be adjusted bysuitable adjusting means, the screw 34 representing such means. Withreference to FlGS. 3 and 4, it will be noted that the arbor surface 23and the pitch tool surface 31 are mutually perpendicular, the arborsurface 23 extending axially beyond the forward edge 35 of the member 30toward the coiling point surface 27.

Referring now to FIGS. 2 and 5, the block 28 upon which the abutmentsurface 27 is located is mounted on the outer end 40 of a lever 41secured at its other end 42 to a rotatably mounted axle 44, theconnection between the lever 41 and the axle 44 being at right angles.Adjustment screws 46 and 47 are provided for limiting the angularmovement of the lever 41, the surface 27 being in its first end positionwhen the lever 41 is in engagement with the screw 46 and in its secondend position when the lever 41 is in engagement with the screw 47. Sincethe total movement of the surface 27 is quite small relative to thelength of the lever 41, motion of the surface 27 may be described asbeing translational in character, and the surface 27 may be said to bereciprocated between its end positions. The axle 44 is connected atright angles at its other end to a lever 50 supporting a rotatable camfollower 51 at its remote end 52. The cam follower 51 rides on theperiphery of a generally circular cam 53 fixed to a rotatably mountedshaft 54. A tension spring 55 along with the pressure of the wire 13 onthe surface 27 biases the cam follower 51 into engagement with theperiphery of the cam 53.

As illustrated by HO. 6, the cam 53 has a first set of constant radiusperipheral portions 56 peripherally spacedapart around the earn, theradius R of these portions 56 being selected to move the abutmentsurface 27 to its first end position whenever the cam follower 51 is incontact with one of these portions 56. A second set of constant radiusperipheral portions 58 are alternated with the portions 56 about theperiphery of the cam 53, the radius R of these portions 58 beingselected to permit the abutment surface 27 to move its second endposition whenever the cam follower 51 is in contact with one of theseportions. The first and second sets of portions 56 and 58 thusconstitute an even number of constant radius portions interconnected byan even number of relatively short transition peripheral portions 60. Bymaking the angular extents of the portions 56 and 58 large relative tothe portions 60 and by rotating the cam 53 at a constant rate, theabutment surface 27 will be reciprocated in the manner described above,dwelling at its end positions a much longer time than utilized in movingbetween its end positions. As illustrated, the portions 56 have twicethe angular extent of the portions 58, the result being that the smallradius portions of the coils formed will have substantially twice thelength of wire as the large radius portions. Similarly, the portions 56have approximately four times the angular extent of the transitionportions 60. It will, of course, occur to those skilled in the art thatthe relative angular extents can be different to provide differentrelative lengths of wire in the different radius portions ofthe coils.

Attention is now directed to FIGS. 1 and 6. To assure coordination ofmovement of the wire 13 along the longitudinal axis 16 and reciprocationof the surface 27, the shaft 54 carrying the cam 53 has a sprocket 62fixed thereto for rotation therewith. An idle shaft 66 rotatably mountedin the machine 10 has a pair of similar sprockets 64 and 65 fixedthereto, and a shaft 67 connected to at least one of the rollers 15 hasa pair of sprockets 68 and 69 fixed thereto. The electric motor 18drives, through a brake mechanism 100, a sprocket 70, which ispositively connected to the sprocket 69 by a continuous chain 72 suchthat the roller 15 is driven at a constant speed by the motor 18. Thesprockets 68 and 65 are similarly connected by a chain 73, and thesprockets 64 and 62 are interconnected by a chain 75. In this manner,the motor 18 drives not only the roller 15 at a constant speed, but alsothe cam 53. Furthermore, the positive interconnection thus provided bythe chains assures the predetermined relationship between movement ofthe wire 13 and the abutment surface 27 even if for some reason theroller 15 and the cam 53 are not driven at the desired constant rate.

As just described, a continuous spring will be formed by the machine 10.It is, however, usually necessary to cut the continuous spring atpredetermined intervals to form springs of proper length. To accomplishthis is an accurate and efficient manner, a disc 80, as illustrated byH05. 1 and 5, is fixed to the shaft 54, the disc having a number of camlobes 81 projecting radially therefrom for use in counting the number ofcoils formed. There are the same number of lobes 81 as there areconstant radius portions 56, the same number of coils being formed foreach full revolution of the cam 53 and the disc 80 (one large radiusportion to each coil) as there are constant radius portions 56. A switch83 is mounted adjacent the disc 80 in a position to be contacted andclosed by each lobe 81 as it passes the switch 83 during rotation of thedisc 80. Actuation of the switch 83 by each lobe 81 indicates to acontrol device 85 through a suitable circuit 86 that a single coil hasbeen formed. The control device 85 counts the coils indicated in thismanner and, when a predetermined number have been formed, signals acutoff mechanism 90 illustrated by FIG. 1 to cut the wire intermediatethe surfaces 27 and 31.

The cutoff mechanism 90 includes shears 92 carried by a support 93 whichis reciprocably mounted on a slide 94 for movement between a firstposition in which the cutting shears 92 are remote from the coil formingmeans and a second position in which the cutting shears 92 arepositioned to cut the wire 13, the first position shown by solid linesand the second position by broken lines. The cutoff mechanism 90 alsoincludes an actuating mechanism 95 for operating the shears 92 and afluid actuator 96 for moving the support 93 along the slide 94 betweenits first and second positions. In operation, upon the formation of apredetermined number of coils, the control device 85 sequentially causesthe actuator 96 to move the support 93 and the shears 92 from the firstposition into the second cutting position, the actuating mechanism 95 tooperate the shears 92 to cut the wire, and the actuator 96 to return thesupport 93 and the shears 92 to the first position.

The control device 85 also actuates the brake mechanism 100 to stop thefeed of the wire 13 and the reciprocation of the surface 27 during thecutoff operation. After the wire is cut, the brake 100 is released andthe roller 15 again feeds the wire and the surface 27 is againreciprocated to form the coils of a new spring. On the other hand, thewire 13 may be cut while being continuously advanced through themachine. In either event, however, the cam lobes 81 on the disc 80should be positioned to cause the wire 13 to be cut at the proper point,it being recognized that the wire 13 will in either case be advanced toa limited extent before the actual cutting occurs after the controldevice 85 signals the cutoff mechanism 96 that the predetermined numberof coils have been formed.

While the arrangement of FIGS. 1-6 is the presently preferred form ofthe invention, it will be obvious to those skilled in the art thatalternative arrangements can be utilized in the practice of theinvention. For example, FIG. 7 illustrates an arrangement in which apressure actuator 102 and valve means 103 are used in place of the cam53 and its associated apparatus. More particularly, the pressureactuator 102 includes a cylinder 105 pivotally secured to the machine 10at 106 and a piston 107 slidably mounted within the cylinder 105. Aconnecting rod 108 connects the piston 107 to a block 23 having anabutment surface 27 thereon for reciprocating the block 28 between afirst position illustrated by solid lines and a second positionillustrated by broken lines. The valve mechanism 103 selectivelysupplies pressurized fluid from a source 110 to a selected one of thecylinder regions 112 and 113. When the actuating fluid is supplied toregion 112, the piston 107 is moved to the right and the surface 27 ismoved to its first position, and when the fluid is supplied to region113, the piston 107 is moved to the left and the surface 27 is moved toits second position. Movement of the piston 107 must, of course, becoordinated with movement of the wire 13' by the roller This may beaccomplished by mounting a disc 116 on the drive shaft 67' and locatingsuitable cam lobes 118 on the disc 116 for indicating formation of thevarious constant and variable radius portions of the coils. These camlobes 118 actuate switches 120 to indicate to a control device 121 forthe valve mechanism 103 the formation of each coil portion.

From the foregoing, it will be appreciated that the coil winding methodand machine of this invention automatically produces coil springs of thenonuniform radii type in a rapid, efficient and accurate manner.

it will be understood that the invention is not limited to the specificdetails of the construction and arrangement of the illustratedembodiments since changes and modifications will be obvious to thoseskilled in the art. It is therefore intended to cover in the appendedclaims all such changes and modifications which may occur to thoseskilled in the art without departing from the true spirit and scope ofthe invention.

lclaim:

1. Coil springrwinding apparatus comprising:

means for supporting and guiding a wire along a longitudinal axis, saidsupporting and guiding means including a discharge portion,

forming means adjacent said discharge portion for bending a wiredischarged from said discharge portion, said forming means includingabutment means mounted for reciprocable movement between first andsecond end positions,

said abutment means in said first and second end positions extendingtransversely of said longitudinal axis in axiallyspaced relationship tosaid discharge portion such that a wire discharged from said dischargeportion contacts said abutment means and is thereby deflected out ofsaid longitudinal axis into a curved configuration,

the axial spacing between said abutment means and said discharge portionbeing greater in said second end position than in said first endposition such that the radius of curvature of the wire portions fonnedwhen said abutment means is in said second end position is greater thanthe radius of curvature of the wire portions formed when said abutmentmeans is in said first end position,

said supporting and guiding means further including means for advancinga wire through said discharge portion into contact with said abutmentmeans,

means for moving said abutment means alternately between said first andsecond end positions,

and control means operatively connected to and coordinating theoperation of both said wire advancing means and said means for movingsaid abutment means such that relatively small movement of the wireoccurs during movement in either direction of said abutment meansbetween said end positions and relatively large movement of the wireoccurs when said abutment means is in either of said endpositions,

whereby a coil spring wound on said coil spring winding apparatusincludes a series of connected identical coils each having a portion ofrelatively small substantially constant radius formed when said abutmentmeans is in said first end position, a portion of relatively largesubstantially constant radius formed when said abutment means is in saidsecond end position, and portions of varying radius formed when saidabutment means is being moved between said end positions, the constantradius portions being long relative to the varying radius portions.

2. Coil spring winding apparatus as defined by claim 1 in which saidforming means further comprises stationary arbor means adjacent saiddischarge portion, said arbor means having a smoothly curved bendingsurface substantially tangent to said longitudinal axis adjacent saiddischarge portion and extending therefrom axially and laterally awayfrom said discharge portion such that a wire deflected away from saidlongitudinal axis by said abutment means is bent around and accuratelyshaped by said curved bending surface.

3. Coil spring winding apparatus as defined by claim 1 in which saidforming means further comprises:

pitch forming means positioned to longitudinally stretch the coils toprovide a desired pitch, said pitch forming means being laterally offsetfrom said longitudinal axis in a direction substantially normal to theplane in which the.

coils are formed,

and adjusting means for selectively varying the amount of lateral offsetof said pitch forming means so as to thereby permit variation of thedesired pitch.

4. Coil spring winding apparatus as defined by claim 1 furthercomprising automatic cutoff means for counting the number of coilsformed and cutting the wire after a predetermined number of coils havebeen formed to form a spring of predetermined length.

5. Coil spring winding apparatus as. defined by claim 1 in which:

said wire advancing means includes at least one rotatably mounted rollerpositioned to engage and force a wire through said supporting andguiding means;

said means for moving said abutment means comprises:

a rotatably mounted cam having an even number of angularly spaced-apartconstant radius peripheral portions thereon and an even number ofvariable radius transition peripheral portions interconnecting saidconstant radius portions, a first set of alternate ones of said constantradius portions having identical angular extents and identical radii anda second set of alternate ones of said constant radius portions havingidentical angular extents and identical radii different than theidentical radii of said first set, the angular extents. of. each of saidconstant radius portions being long relative to the angular extents ofsaid transition portions,

a cam follower biased into contact with the periphery of said cam,

and means connecting said cam follower and said abutment means forvarying the position of said abutment means in accordance with theangular position of said cam;

said control means including means positively interconnecting saidroller and said cam such that there is a direct relationship betweenlongitudinal feed of a wire by said roller and movement of said abutmentmeans.

6. Coil spring winding apparatus as defined by claim 5 in which theangular extent of each of the constant radius portions of said first setis approximately twice the angular extent of each of the constant radiusportions of said second set.

7. Coil spring winding apparatus as defined by claim 6 in which theangular extent of each of the constant radius portions of said first andsecond sets is substantially greater than the angular extent of thetransition portions.

0. Coil spring winding apparatus as'defined by claim 7 in which theratio of the axial distance between said abutment means and saiddischarge portion in said second and first end positions, respectively,is 1.422.

9. Coil spring winding apparatus as defined by claim in which saidforming means further comprises stationary arbor means about which awire deflected away from said longitudinal axis by said abutment meansmay be bent and shaped, said stationary arbor means being positionedadjacent said discharge portion and being laterally offset from saidlongitudinal axis.

10. Coil spring winding apparatus as defined by claim 9 in which saidforming means further comprises:

pitch forming means positioned to longitudinally stretch the coils toprovide a desired pitch, said pitch forming means being laterally offsetfrom said longitudinal axis along a direction substantially normal tothe direction of lateral offset of said arbor means,

and adjusting means for selectively varying the amount of lateral offsetof said pitch forming means so as to thereby pennit variation of thedesired pitch.

1]. Coil spring winding apparatus as defined by claim 9 in which saidabutment means includes a flat substantially smooth surface axiallyfacing said discharge portion and said arbor means includes a smoothlycurved bending surface substantially tangent to said longitudinal axisadjacent said discharge portion and extending therefrom axially andlaterally away from said discharge portion, said forming means furthercomprising:

pitch forming means including a flat substantially smooth surface overwhich the coils are directed after being deflected by said flat abutmentsurface, said pitch forming surface being laterally offset from saidlongitudinal axis,

said smoothly curved bending surface being substantially perpendicularto said pitch forming surface and extending axially beyond said pitchforming surface toward said abutment surface,

and adjusting means for selectively varying the amount of lateral offsetof said pitch forming surface so as to thereby permit variation of thedesired pitch.

l2. Coil spring winding apparatus as defined by claim 5 furthercomprising:

a plurality of shafts,

bearing means supporting each of said shafts for rotation about itsaxis,

said roller and said cam fixed to respective ones of said shafts forrotation therewith,

a plurality of driven sprockets fixed to respective ones of said shafts,

drive means,

a driving sprocket rotatably driven by said drive means,

and chain means interconnecting said driving and said driven sprocketssuch that all of said shafts and consequently said roller and said camrotate in unison at fixed ratios therebetween. l3. Coil spring windingapparatus as defined by claim 12 in which said means connecting said camfollower and said abutment means comprises:

a rotatably mounted axle, a first lever secured at a first end to saidabutment means and at a second end to said axle at right angles thereto,

and a second lever secured at a first end to said cam follower and at asecond end to said axle at right angles thereto, whereby movement ofsaid cam follower by said rotating cam is converted into correspondingmovement of said abutment means,

the elements of said connecting means being arranged such that thepressure of a wire contacting said abutment means biases said camfollower against the periphery of said cam and such that said abutmentmeans is in said first end position when said cam follower is in contactwith the larger radius peripheral portions of said cam and in saidsecond end position when said cam follower is in contact with thesmaller radius peripheral portions of said cam.

14. Coil spring winding apparatus as defined by claim 13 furthercomprising automatic cutoff means for counting the number of coilsformed and cutting the wire after a predetermined number of coils havebeen formed to form a spring of predetermined length.

15. Coil spring winding apparatus as defined by claim R3 in which saidabutment means includes a flat substantially smooth surface axiallyfacing said discharge portion, said forming means further comprising:

stationary arbor means about which a wire deflected away from saidlongitudinal axis by said abutment surface may be bent and accuratelyshaped, said arbor means including a smoothly curved bending surfacesubstantially tangent to said longitudinal axis adjacent said dischargeportion and extending therefrom axially and laterally away from saiddischarge portion,

pitch forming means including a flat substantially smooth surface overwhich the coils are directed after being deflected by said flat abutmentsurface, said pitch forming surface being laterally offset from saidlongitudinal axis,

said smoothly curved bending surface being substantially perpendicularto said pitch forming surface and extending axially beyond said pitchforming surface toward said abutment surface,

and adjusting means for selectively varying the amount of lateral offsetof said pitch forming surface so as to thereby permit variation of thedesired pitch.

l6. Coil spring winding apparatus as defined by claim 15 furthercomprising:

cutting means,

means supporting and moving said cutting means between a first positionremote from said forming means and a second position adjacent saidforming means in which said cutting means is positioned to cut a wiredischarged from said discharge portion,

means associated with said roller and said cam for indicating theformation of each coil,

and cutting means interconnecting said indicating means,

said cutting means, and said support means,

said cutting control means counting the number of coils formed asindicated by said indicating means and, upon the fonnation of apredetermined number of coils, sequentially causing said support meansto move said cutting means from said first position to said secondposition, said cutting means to cut the wire adjacent said dischargeportion, and said support means to return said cutting means to saidfirst position from said second position.

17. Coil spring winding apparatus as defined by claim 16 furthercomprising brake means associated with said drive means for selectivelystopping and permitting movement of said shafts and consequently saidroller and said cam, said control also being connected to said brakemeans to cause said brake means to stop said shafts upon formation ofsaid predetermined number of coils and to release said shafts after saidcutting means has cut the wire.

18. Coil spring winding apparatus as defined by claim 16 in which saidindicating means comprises:

a circular disc secured to the shaft supporting said cam for rotationwith said cam,

a plurality of cam lobes secured to said disc and projecting radiallytherefrom, said lobes being peripherally equally spaced and there beingone-half as many lobes as there are constant radius peripheral portionson said cam,

switch means adjacent said disc positioned for sequential actuation bysaid lobes during rotation of said disc,

and means interconnecting said switch means and said cutting controlmeans such that momentary actuation of said switch means by each lobeindicates to said cutting control means the formation of a single coil.

19. Coil spring winding apparatus as defined by claim 1 in which:

said wire advancing means includes at least one rotatably mounted rollerpositioned to engage and force a wire through said supporting andguiding means;

said means for moving said abutment means comprises:

a double-acting-fluid pressure actuator including a cylinder and apiston slidably mounted within said cylinder for movement thereinbetween first and second positions relative to said cylinder;

means securing one of said cylinder and said piston in a fixed positionand means securing the other of said cylinder and said piston to saidabutment means,

said abutment means being in said first end position when said cylinderand said piston are in said first relative position and in said secondend position when said cylinder and said piston are in said secondrelative position,

and valve means for supplying pressurized fluid to said actuator forselectively moving said cylinder and said piston between said first andsecond relative positions.

20. Coil spring winding apparatus as defined by claim 19 in which saidabutment means includes a flat substantially smooth surface axiallyfacing said discharge portion, said forming means further comprising:

stationary arbor means about which a wire deflected away from saidlongitudinal axis by said abutment surface may be bent and accuratelyshaped, said arbor means including a smoothly curved bending surfacesubstantially tangent to said longitudinal axis adjacent said dischargeportion and extending therefrom axially and laterally away from saiddischarge portion,

pitch forming means including a flat substantially smooth surface overwhich the coils are directed after being deflected by said flat abutmentsurface, said pitch forming surface being laterally offset from saidlongitudinal axis,

said smoothly curved bending surface being substantially perpendicularto said pitch forming surface and extending axially beyond said pitchforming surface toward said abutment surface,

and adjusting means for selectively varying the amount of lateral offsetof said pitch forming surface so as to thereby permit variation of thedesired pitch.

21. A method of winding coil springs comprising:

supplying wire to a bending location at a substantially constant feedrate,

bending the wire supplied to the bending location into a coil besequentially bending the wire;

at a first fixed radius of curvature for a first predetermined period oftime,

at a variable radius of curvature for a second predetermined period oftime,

at a second fixed radius of curvature for a third predetermined periodof time,

and at a variable radius of curvature for a fourth predetermined periodof time,

said first and third periods of time being substantially longer thansaid second and fourth periods of time and the variable radii ofcurvature of the wire portions formed during said second and fourthperiods of time varying gradually between said first and said secondfixed radii of curvature and said second and said first fixed radii ofcurvature, respectively.

22. A method of winding coil springs as defined by claim 21 furthercomprising repeating said sequential bending steps a predeterminednumber of times and then cutting the wire so as to form a spring havinga predetermined number of coils.

23. A method of winding coil springs as defined by claim 22 furthercomprising continuously stretching said coiled wire substantially normalto the plane in which the coils are formed to provide a predeterminedconstant pitch.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,576,120 Dated April 27, 1971 It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 1, line 60, delete "and";

Column 3, line 3, after "surface 27" insert such Column 4, line 25,change "is" to in Column 8, line 37 after "cutting" insert controlColumn 10, line 10, change "be" to by Signed and sealed this 26th day ofOctober 1 971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTISCHALK Attesting Officer ActingCommissioner of Patents

1. Coil spring winding apparatus comprising: means for supporting andguiding a wire along a longitudinal axis, said supporting and guidingmeans including a discharge portion, forming means adjacent saiddischarge portion for bending a wire discharged from said dischargeportion, said forming means including abutment means mounted forreciprocable movement between first and second end positions, saidabutment means in said first and second end positions extendingtransversely of said longitudinal axis in axiallyspaced relationship tosaid discharge portion such that a wire discharged from said dischargeportion contacts said abutment means and is thereby deflected out ofsaid longitudinal axis into a curved configuration, the axial spacingbetween said abutment means and said discharge portion being greater insaid second end position than in said first end position such that theradius of curvature of the wire portions formed when said abutment meansis in said second end position is greater than the radius of curvatureof the wire portions formed when said abutment means is in said firstend position, said supporting and guiding means further including meansfor advancing a wire through said discharge portion into contact withsaid abutment means, means for moving said abutment means alternatelybetween said first and second end positions, and control meansoperatively connected to and coordinating the operation of both saidwire advancing means and said means for moving said abutment means suchthat relatively small movement of the wire occurs during movement ineither direction of said abutment means between said end positions andrelatively large movement of the wire occurs when said abutment means isin either of said end positions, whereby a coil spring wound on saidcoil spring winding apparatus includes a series of connected identicalcoils each having a portion of relatively small substantially constantradius formed when said abutment means is in said first end position, aportion of relatively large substantially constant radius formed whensaid abutment means is in said second end position, and portions ofvarying radius formed when said abutment means is being moved betweensaid end positions, the constant radius portions being long relative tothe varying radius portions.
 2. Coil spring winding apparatus as definedby claim 1 in which said forming means further comprises stationaryarbor means adjacent said discharge portion, said arbor means having asmoothly curved bending surface substantially tangent to saidlongitudinal axis adjacent said discharge portion and extendingtherefrom axially and laterally away from said discharge portion suchthat a wire deflected away from said longitudinal axis by said abutmentmeans is bent around and accurately shaped by said curved bendingsurface.
 3. Coil spring winding apparatus as defined by claim 1 in whichsaid forming means further comprises: pitch forming means positioned tolongitudinally stretch the coils to provide a desired pitch, said pitchforming means being laterally offset from said longitudinal axis in adirection substantially normal to the plane in which the coils areformed, and Adjusting means for selectively varying the amount oflateral offset of said pitch forming means so as to thereby permitvariation of the desired pitch.
 4. Coil spring winding apparatus asdefined by claim 1 further comprising automatic cutoff means forcounting the number of coils formed and cutting the wire after apredetermined number of coils have been formed to form a spring ofpredetermined length.
 5. Coil spring winding apparatus as defined byclaim 1 in which: said wire advancing means includes at least onerotatably mounted roller positioned to engage and force a wire throughsaid supporting and guiding means; said means for moving said abutmentmeans comprises: a rotatably mounted cam having an even number ofangularly spaced-apart constant radius peripheral portions thereon andan even number of variable radius transition peripheral portionsinterconnecting said constant radius portions, a first set of alternateones of said constant radius portions having identical angular extentsand identical radii and a second set of alternate ones of said constantradius portions having identical angular extents and identical radiidifferent than the identical radii of said first set, the angularextents of each of said constant radius portions being long relative tothe angular extents of said transition portions, a cam follower biasedinto contact with the periphery of said cam, and means connecting saidcam follower and said abutment means for varying the position of saidabutment means in accordance with the angular position of said cam; saidcontrol means including means positively interconnecting said roller andsaid cam such that there is a direct relationship between longitudinalfeed of a wire by said roller and movement of said abutment means. 6.Coil spring winding apparatus as defined by claim 5 in which the angularextent of each of the constant radius portions of said first set isapproximately twice the angular extent of each of the constant radiusportions of said second set.
 7. Coil spring winding apparatus as definedby claim 6 in which the angular extent of each of the constant radiusportions of said first and second sets is substantially greater than theangular extent of the transition portions.
 8. Coil spring windingapparatus as defined by claim 7 in which the ratio of the axial distancebetween said abutment means and said discharge portion in said secondand first end positions, respectively, is 1.422.
 9. Coil spring windingapparatus as defined by claim 5 in which said forming means furthercomprises stationary arbor means about which a wire deflected away fromsaid longitudinal axis by said abutment means may be bent and shaped,said stationary arbor means being positioned adjacent said dischargeportion and being laterally offset from said longitudinal axis.
 10. Coilspring winding apparatus as defined by claim 9 in which said formingmeans further comprises: pitch forming means positioned tolongitudinally stretch the coils to provide a desired pitch, said pitchforming means being laterally offset from said longitudinal axis along adirection substantially normal to the direction of lateral offset ofsaid arbor means, and adjusting means for selectively varying the amountof lateral offset of said pitch forming means so as to thereby permitvariation of the desired pitch.
 11. Coil spring winding apparatus asdefined by claim 9 in which said abutment means includes a flatsubstantially smooth surface axially facing said discharge portion andsaid arbor means includes a smoothly curved bending surfacesubstantially tangent to said longitudinal axis adjacent said dischargeportion and extending therefrom axially and laterally away from saiddischarge portion, said forming means further comprising: pitch formingmeans including a flat substantially smooth surface over which the coilsare directed after being deflected by said flat abutment surface, saidpitch forming surface bEing laterally offset from said longitudinalaxis, said smoothly curved bending surface being substantiallyperpendicular to said pitch forming surface and extending axially beyondsaid pitch forming surface toward said abutment surface, and adjustingmeans for selectively varying the amount of lateral offset of said pitchforming surface so as to thereby permit variation of the desired pitch.12. Coil spring winding apparatus as defined by claim 5 furthercomprising: a plurality of shafts, bearing means supporting each of saidshafts for rotation about its axis, said roller and said cam fixed torespective ones of said shafts for rotation therewith, a plurality ofdriven sprockets fixed to respective ones of said shafts, drive means, adriving sprocket rotatably driven by said drive means, and chain meansinterconnecting said driving and said driven sprockets such that all ofsaid shafts and consequently said roller and said cam rotate in unisonat fixed ratios therebetween.
 13. Coil spring winding apparatus asdefined by claim 12 in which said means connecting said cam follower andsaid abutment means comprises: a rotatably mounted axle, a first leversecured at a first end to said abutment means and at a second end tosaid axle at right angles thereto, and a second lever secured at a firstend to said cam follower and at a second end to said axle at rightangles thereto, whereby movement of said cam follower by said rotatingcam is converted into corresponding movement of said abutment means, theelements of said connecting means being arranged such that the pressureof a wire contacting said abutment means biases said cam followeragainst the periphery of said cam and such that said abutment means isin said first end position when said cam follower is in contact with thelarger radius peripheral portions of said cam and in said second endposition when said cam follower is in contact with the smaller radiusperipheral portions of said cam.
 14. Coil spring winding apparatus asdefined by claim 13 further comprising automatic cutoff means forcounting the number of coils formed and cutting the wire after apredetermined number of coils have been formed to form a spring ofpredetermined length.
 15. Coil spring winding apparatus as defined byclaim 13 in which said abutment means includes a flat substantiallysmooth surface axially facing said discharge portion, said forming meansfurther comprising: stationary arbor means about which a wire deflectedaway from said longitudinal axis by said abutment surface may be bentand accurately shaped, said arbor means including a smoothly curvedbending surface substantially tangent to said longitudinal axis adjacentsaid discharge portion and extending therefrom axially and laterallyaway from said discharge portion, pitch forming means including a flatsubstantially smooth surface over which the coils are directed afterbeing deflected by said flat abutment surface, said pitch formingsurface being laterally offset from said longitudinal axis, saidsmoothly curved bending surface being substantially perpendicular tosaid pitch forming surface and extending axially beyond said pitchforming surface toward said abutment surface, and adjusting means forselectively varying the amount of lateral offset of said pitch formingsurface so as to thereby permit variation of the desired pitch.
 16. Coilspring winding apparatus as defined by claim 15 further comprising:cutting means, means supporting and moving said cutting means between afirst position remote from said forming means and a second positionadjacent said forming means in which said cutting means is positioned tocut a wire discharged from said discharge portion, means associated withsaid roller and said cam for indicating the formation of each coil, andcutting means interconnecting said indicating means, said cutting means,and said support meaNs, said cutting control means counting the numberof coils formed as indicated by said indicating means and, upon theformation of a predetermined number of coils, sequentially causing saidsupport means to move said cutting means from said first position tosaid second position, said cutting means to cut the wire adjacent saiddischarge portion, and said support means to return said cutting meansto said first position from said second position.
 17. Coil springwinding apparatus as defined by claim 16 further comprising brake meansassociated with said drive means for selectively stopping and permittingmovement of said shafts and consequently said roller and said cam, saidcontrol also being connected to said brake means to cause said brakemeans to stop said shafts upon formation of said predetermined number ofcoils and to release said shafts after said cutting means has cut thewire.
 18. Coil spring winding apparatus as defined by claim 16 in whichsaid indicating means comprises: a circular disc secured to the shaftsupporting said cam for rotation with said cam, a plurality of cam lobessecured to said disc and projecting radially therefrom, said lobes beingperipherally equally spaced and there being one-half as many lobes asthere are constant radius peripheral portions on said cam, switch meansadjacent said disc positioned for sequential actuation by said lobesduring rotation of said disc, and means interconnecting said switchmeans and said cutting control means such that momentary actuation ofsaid switch means by each lobe indicates to said cutting control meansthe formation of a single coil.
 19. Coil spring winding apparatus asdefined by claim 1 in which: said wire advancing means includes at leastone rotatably mounted roller positioned to engage and force a wirethrough said supporting and guiding means; said means for moving saidabutment means comprises: a double-acting fluid pressure actuatorincluding a cylinder and a piston slidably mounted within said cylinderfor movement therein between first and second positions relative to saidcylinder; means securing one of said cylinder and said piston in a fixedposition and means securing the other of said cylinder and said pistonto said abutment means, said abutment means being in said first endposition when said cylinder and said piston are in said first relativeposition and in said second end position when said cylinder and saidpiston are in said second relative position, and valve means forsupplying pressurized fluid to said actuator for selectively moving saidcylinder and said piston between said first and second relativepositions.
 20. Coil spring winding apparatus as defined by claim 19 inwhich said abutment means includes a flat substantially smooth surfaceaxially facing said discharge portion, said forming means furthercomprising: stationary arbor means about which a wire deflected awayfrom said longitudinal axis by said abutment surface may be bent andaccurately shaped, said arbor means including a smoothly curved bendingsurface substantially tangent to said longitudinal axis adjacent saiddischarge portion and extending therefrom axially and laterally awayfrom said discharge portion, pitch forming means including a flatsubstantially smooth surface over which the coils are directed afterbeing deflected by said flat abutment surface, said pitch formingsurface being laterally offset from said longitudinal axis, saidsmoothly curved bending surface being substantially perpendicular tosaid pitch forming surface and extending axially beyond said pitchforming surface toward said abutment surface, and adjusting means forselectively varying the amount of lateral offset of said pitch formingsurface so as to thereby permit variation of the desired pitch.
 21. Amethod of winding coil springs comprising: supplying wire to a bendinglocation at a substantially constant feed rAte, bending the wiresupplied to the bending location into a coil be sequentially bending thewire; at a first fixed radius of curvature for a first predeterminedperiod of time, at a variable radius of curvature for a secondpredetermined period of time, at a second fixed radius of curvature fora third predetermined period of time, and at a variable radius ofcurvature for a fourth predetermined period of time, said first andthird periods of time being substantially longer than said second andfourth periods of time and the variable radii of curvature of the wireportions formed during said second and fourth periods of time varyinggradually between said first and said second fixed radii of curvatureand said second and said first fixed radii of curvature, respectively.22. A method of winding coil springs as defined by claim 21 furthercomprising repeating said sequential bending steps a predeterminednumber of times and then cutting the wire so as to form a spring havinga predetermined number of coils.
 23. A method of winding coil springs asdefined by claim 22 further comprising continuously stretching saidcoiled wire substantially normal to the plane in which the coils areformed to provide a predetermined constant pitch.